dmac (Customer) asked a question.

June 17, 2020 at 3:42 AM
How to test the KN-F10L24DC fuse block LED. I am unable to get the LED to illuminate with a good fuse, blown fuse or no fuse installed. I don't see how to test the LED? Any ideas as I have several of the 24 VDC terminal blocks and none of them work.
  • 5 answers
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  • ADC Community_02 (Automationdirect.com)

    Do you have a load connected to the terminal block?

     

    We tested here and if you only have 24V connected the light will not work as expected. Therefore, if you wire it normally with a load the light will work if a fuse is not present or blown.

     

    Picture showing light illuminated with load applied:

    LedKNF10

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  • dmac (Customer)

    ScreenHunter 581IMG_6287IMG_3840Thanks for the quick reply.

    I have a couple of questions as follows:

    1. Does it matter which the fuse block is installed? I have it installed with the +24 VDC coming into the end opposite of the LED. I reversed it at one time but it did not help.
    2. How much load does the fuse block need? I am using a loop simulator to vary the 4-20 input signal which is the only load on the fuse.

    The intent was to protect the system when someone grounded the 24 VDC loop power supply going to the field mounted pressure transmitter (4-20 mA input to terminals 9 & 10)..

    Which raises another question: What happens if the 4-20 mA output signal is shorted in the field?

    Any Suggestions or recommendations?

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  • ADC Community_02 (Automationdirect.com)

    What happens if you put a 24Vdc light in the circuit or a volt meter instead of using the calibrator. Does it function correctly?

     

    I sent your questions to the Product Engineer for this product and will update this thread once I hear back from him.

  • dmac (Customer)

    Thanks for the response.

    I had the alarm LED hooked up just to see if it would help. No change.

    Based on the input I decided to test the fuse terminal with a 24 VDC relay I had (see pic)

    I wired like installed in box and relay worked but LED did not come on. Turned fuse block around so +24 VDC came in on the side that has the LED. It worked.

    Rewired main panel which amounted to swapping ends on the fuse terminal and restoring the LED connection to original location. The LED on fuse block works now. So I am very happy Thanks.

    It appears the fuse terminal block needs to have a load - when I removed the wire the LED did not come on.

    That solved that issue so thanks for your help.

    I have not reversed the AC fuse block and the LED comes on when I open the fuse block. Should it be reversed?

    Test Fuse Block with Relay

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